Use CallBootstrapC stub for leaf native calls.

runtime/vm/stub_code_arm.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/cpu.h"
@@ skipping 198 matching lines @@
 
   ASSERT(retval_offset == 3 * kWordSize);
   __ add(R3, FP, Operand(3 * kWordSize));  // Set retval in NativeArgs.
 
   // Passing the structure by value as in runtime calls would require changing
   // Dart API for native functions.
   // For now, space is reserved on the stack and we pass a pointer to it.
   __ stm(IA, SP,  (1 << R0) | (1 << R1) | (1 << R2) | (1 << R3));
   __ mov(R0, Operand(SP));  // Pass the pointer to the NativeArguments.
 
-  // Call native function (setsup scope if not leaf function).
-  Label leaf_call;
-  Label done;
-  __ TestImmediate(R1, NativeArguments::AutoSetupScopeMask());
-  __ b(&leaf_call, EQ);
-
   __ mov(R1, Operand(R5));  // Pass the function entrypoint to call.
   // Call native function invocation wrapper or redirection via simulator.
 #if defined(USING_SIMULATOR)
   uword entry = reinterpret_cast<uword>(NativeEntry::NativeCallWrapper);
   entry = Simulator::RedirectExternalReference(
       entry, Simulator::kNativeCall, NativeEntry::kNumCallWrapperArguments);
   __ LoadImmediate(R2, entry);
   __ blx(R2);
 #else
   __ BranchLink(&NativeEntry::NativeCallWrapperLabel());
 #endif
-  __ b(&done);
-
-  __ Bind(&leaf_call);
-  // Call native function or redirection via simulator.
-  __ blx(R5);
-
-  __ Bind(&done);
 
   // Mark that the isolate is executing Dart code.
   __ LoadImmediate(R2, VMTag::kScriptTagId);
   __ StoreToOffset(kWord, R2, CTX, Isolate::vm_tag_offset());
 
   // Reset exit frame information in Isolate structure.
   __ LoadImmediate(R2, 0);
   __ StoreToOffset(kWord, R2, CTX, Isolate::top_exit_frame_info_offset());
 
   // Load Context pointer from Isolate structure into R2.
@@ skipping 1590 matching lines @@
   const Register right = R0;
   __ ldr(left, Address(SP, 1 * kWordSize));
   __ ldr(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM